ICMP and connection tracking

[Aleksandar Milivojevic <amilivojevic@xxxxxx>]

Are ICMP packets related to new and established TCP connections and UDP 
traffic considered to be part of them, or do I need to have explicit 
rules like

   -A INPUT -p icmp -m state --state RELATED -j ACCEPT

for things like path MTU discovery, traceroute, ICMP port unreachables, 
and so on to work properly?

Any downsides of using generic rule like above (if it is needed)?

--
Aleksandar Milivojevic <amilivojevic@xxxxxx>    Pollard Banknote Limited
Systems Administrator                           1499 Buffalo Place
Tel: (204) 474-2323 ext 276                     Winnipeg, MB  R3T 1L7